comp
Class FuncDefNode

java.lang.Object
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  +--comp.Node
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        +--comp.FuncDefNode

class FuncDefNode

extends Node

A function definition. Consists of a parameter list, a body, and a scope.

See Also:

ParmList, Scope, BlockNode

Field Summary

(package private) BlockNode	block
(package private) java.lang.String	id
(package private) ParmList	parms
(package private) java.lang.String	returnLabel
(package private) Scope	scope

Fields inherited from class comp.Node

asm, globalScope, labelCount, strings

Constructor Summary

FuncDefNode(java.lang.String id, ParmList parms, BlockNode b)

Method Summary

void	asHTML(java.io.PrintStream out) Process the parameter list and processeach of the body statements.
java.lang.String	codeGen(Scope s, RegBank bank) We implement a caller-saves register convention, aside for the return address and the frame pointer.
void	makeScope() Create a scope for this function.
java.lang.String	toString()

Methods inherited from class comp.Node

addDefs, addString, getLabel, lvalue, reset, rvalue

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

id

java.lang.String id

parms

ParmList parms

block

BlockNode block

scope

Scope scope

returnLabel

java.lang.String returnLabel

Constructor Detail

FuncDefNode

public FuncDefNode(java.lang.String id,
                   ParmList parms,
                   BlockNode b)

Method Detail

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

codeGen

public java.lang.String codeGen(Scope s,
                                RegBank bank)

We implement a caller-saves register convention, aside for the return address and the frame pointer. On entry, a function must allocate enough space for those two registers PLUS any local variables. The stack is grown by this amount, registers saved, and then the frame pointer is made to indicate the current stack top. This allows us to use the frame pointer to access locals, arguments, etc in a sane manner, while the stack pointer is free to grow and shrink throughout the execution of the body (for doing other calls, etc).

Specified by:

codeGen in class Node

makeScope

public void makeScope()

Create a scope for this function. We make a new empty scope, and then traverse the subtree, adding definitions to it. We could do this during parsing, probably...

asHTML

public void asHTML(java.io.PrintStream out)

Process the parameter list and processeach of the body statements.

Specified by:

asHTML in class Node